108 MEMOIR OF MAGENDIE. 



entirely paralyzed ; it was insensible to punctures and to the strongest pressure ; 

 it seemed also to be immovable. But presently, to my great surprise, I saw it 

 move very apparently, altliougli the sensibility was all the time wholly extinct. 

 A second, a third experiment gave me exactly the same result ; 1 began to regard 

 it as probable that the posterior roots of the rachidian nerves might well have 

 different functions from the anterior roots, and that they were more particularly 

 destined for sensibility. 



"It naturally occurred to my mind to cut the anterior roots, leaving the pos- 

 terior ones undisturbed ; but such an undertaking was more easy to conceive 

 than to execute ; how could it be possible to uncover the anterior part of the 

 medulla without injuring the posterior roots 1 I confest; that at first the thing 

 appeared to me impracticable ; yet for two days I never ceased thinking about 

 it, and finally decided to attempt to pass before the posterior roots a sort of knife 

 for cataract, whose very narrow blade would allow of cutting the roots by press- 

 ing them with the edge of the instrument on the posterior face of the body of 

 the vertebrae ; but I was obliged to renounce this expedient on account of the 

 large veins which the canal contains on that side, and which were opened at every 

 movement in advance. In making these essays, I perceived that by pulling 

 upon the vertebral dura mater I could discern the anterior roots linited in fasci- 

 cles, just when they are about to penetrate that membrane. I wanted nothing 

 more, and in a few moments I had cut all the pairs which I wished to divide. 

 As in the preceding experiments, I made the section only on one side, in order 

 to have a term of comparison. Ifc may readily be conceived with what curiosity 

 I followed the effects of this section, nor were they ambiguous ; the member was 

 completely motionless and lax, while it preserved a sensibility not at all equivo- 

 cal. Finally, to neglect nothing, I have cut at once the anterior and posterior 

 roots ; there was then an absolute loss both of sensibility and movement. 



" I have repeated and varied these experiments on several species of animals ; 

 the results just announced were confirmed in the most complete manner, whether 

 as regards the anterior or posterior members. I am prosecuting the researches, 

 and will give a more detailed account in the coming number ; it suffices that at 

 present 1 am enabled to assert that the anterior and posterior roots of the nerves 

 which issue from the spinal marrow have different functions ; that the posterior 

 appear more particularly destined for sensibility, while the anterior seem more 

 specially connected with movement." 



Having seen the first note of M. Magendie, let us pass to the second ; the 

 retrograde step cannot fail to occasion surprise : 



Note on the functions of the roots of the nerves which spring from the spinal 

 marrow ; October 22, 1822 : "The facts which I announced in the preceding 

 number are too important not to have led me to seek to elucidate them by new 

 researches. I wished first to ascertain if the anterior or the posterior roots of the 

 spinal nerves might not be cut without opening 'the great canal of the vertebral 

 dura mater ; for, by exposing the spinal marrow to the air and to a cold temperature, 

 the nervous action is sensibly enfeebled, and consequently the results sought 

 for are obtained in a manner but little apparent. 



" The anatomical disposition of the parts rendered this not impossible, for each 

 fasciculus of a spinal root proceeds for some time in a particular canal before 

 uniting and being confounded with the other fasciculus. In effect, I have found 

 that by means of scisSors blunted at the point, enough of the films and lateral 

 parts of the vertebra might be removed to expose to view the ganglion of 

 each lumbar pair; and then with a small stylet the canal containing the pos- 

 terior roots may be separated Avithout any insurmountable difiiculty, and there 

 is no further impediment to the accomplishment of the section. This mode of 

 making the experiment has yielded me the same results with those I had already 

 observed; but as the experiment is much longer and more laborious than by 



